On an ATV630, why does the drive ramp all the way to low speed and high speed when my +/- speeds are pulsed?

Issue:
On an ATV630, the drive ramps all the way to low speed and high speed when my +/- speeds are pulsed.

Product Line:
Altivar Machines, Altivar Process Drives

Environment:
All models and serial numbers

Cause:
Drive ramps all the way up and down without stopping in between

Resolution:
This could be caused by any of the following:

• The pulse isn't actually a pulse. Instead you're providing a sustained signal to the digital input
• Acceleration time is too short. +/- speed ramping is based on acceleration speed
• The pulse doesn't drop out long enough for the drive to recognize that it has dropped. Repeated input activation at too high speed can cause this

Try the following:

• Make sure you're actually pulsing the inputs for activation
• Try pulsing the inputs with a jumper wire from +24V to see if the behavior changes
• Adjust acceleration time longer
• Adjust deactivation of the digital inputs to a longer amount of time so the drive realizes the input has deactivated. The drive needs to see the signal drop in order to stop ramping

Released for: Schneider Electric Thailand